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Service bulletins for the 2020 GMC Sierra

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

1990 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Only bulletins with component: Transmission and driveline are shown. Show all

Bulletins, newest first
21-NA-2382024-02-14. Service bulletin. EQUIPMENT; POWER TRAIN. This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak.
PIP5810B2024-02-12. Service bulletin. POWER TRAIN. This Preliminary information communicates that the tool for the HD transfer cases to install the input seal during a repair is incorrect and a new tool is in development.
22-NA-2462024-02-06. Service bulletin. POWER TRAIN. This service bulletin advises the technician that the possible cause may not be from a faulty clutch piston or extension housing and to perform testing on transmission for other possible issues, but it still may be possible on high mileage vehicles that orifices in housing may have come dislodged, causing the same customer concern.
21-NA-1202024-02-05. Service bulletin. EQUIPMENT; POWER TRAIN. This service bulletin provides a Diagnostic Tip for Noise, Vibration, and/or Harshness Issues/Clunk Noise Heard During Coast Down Event after the transfer case was removed from the transmission and reinstalled during a recent repair.
PI1394B2024-02-02. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This PI bulletin advises the technician on the proper way to install the pistons in an engine.
PIT60962024-01-29. Service bulletin. EQUIPMENT:ELECTRICAL; POWER TRAIN. This Preliminary information communicates a diagnostic tip for the 110 /120 volt power outlets being inoperative and dealerships should try a battery disconnect to see if the concern goes away.
23-NA-1852024-01-19. Service bulletin. POWER TRAIN; EQUIPMENT; STEERING; ELECTRICAL SYSTEM. This service bulletin helps diagnose/reduce possible CCND issues on Transfer Cases - Service 4WD on DIC, Intermittent Failures, Noise Concerns, Driveline/Steering Vibration/Shudder, Intermittent DTCs/MIL Illuminated, Engagement/Disengagement/Ratcheting Concerns.
21-NA-2382024-01-19. Service bulletin. POWER TRAIN. This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak.
16-NA-3612024-01-13. Service bulletin. POWER TRAIN; EQUIPMENT. This service bulletin provides service /diagnostic information to aid with a Transmission Harsh 1-2 Shift Upon First Start Up/Shift of the Day Under Light Throttle.
21-NA-1492023-12-19. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN; ENGINE AND ENGINE COOLING. This service bulletin provides repair information for Engine Wire Harness Chafing to correct customer concerns of IPC Gauges Sweep, IPC Warning Message, SES/Check Engine/MIL, No Start/ No Crank, Runs Rough, Stalls, Reduced Engine Power, Various DTCs.
PIT60882023-12-18. Service bulletin. POWER TRAIN; STEERING. This Preliminary information communicates a diagnostic tip to inspect the main ground connection when diagnosing any lack of power steering assist issues with DTCs C1597 and/or C1599.
PIP59492023-12-18. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer, a potential rough running condition following an autostop event that is caused by the incorrect crankshaft position sensor.
PIP59432023-12-04. Service bulletin. EQUIPMENT:MECHANICAL:POWER TAKE-OFF (PTO); POWER TRAIN. This Preliminary Information communication advises the technician on diagnostic aids to help with the diagnosis and repair of 8 Speed Transmissions
22-NA-2512023-11-22. Service bulletin. EQUIPMENT; POWER TRAIN. This service bulletin provides a procedure to replace the front wheel drive shaft to correct a customer concern of a Squeak/Chirp Noise from Front Axle in 2wd.
03-00-91-001I2023-11-22. Service bulletin. WHEELS; POWER TRAIN; STEERING; SUSPENSION; ENGINE AND ENGINE COOLING. This service bulletin provides a vibration analysis worksheet the technician can use in conjunction with the appropriate Vibration Analysis-Road testing procedure when diagnosing vibration concerns.
23-NA-1852023-11-15. Service bulletin. POWER TRAIN; EQUIPMENT; ELECTRICAL SYSTEM; STEERING. This service bulletin helps diagnose/reduce possible CCND issues on Transfer Cases - Service 4WD on DIC, Intermittent Failures, Noise Concerns, Driveline/Steering Vibration/Shudder, Intermittent DTCs/MIL Illuminated, Engagement/Disengagement/Ratcheting Concerns.
22-NA-2252023-11-10. Service bulletin. POWER TRAIN; EQUIPMENT. This information bulletin advises the technician the difference between a welch cap leak and the output seal of the t-case or transmission leaking ATF, causing the customer concern of a Red Fluid Leak from Center of Vehicle Located by Rear of Transmission or Transfer Case Area.
16-NA-3612023-11-10. Service bulletin. POWER TRAIN. This service bulletin provides service /diagnostic information to aid with a Transmission Harsh 1-2 Shift Upon First Start Up/Shift of the Day Under Light Throttle.
21-NA-2752023-11-06. Service bulletin. POWER TRAIN. This service bulletin provides repair information to correct customer concerns of Rear Wheel Lock Up, ABS Event, Loud Bang and a Flashing “D” on Driver Information Center (DIC) when Lightly or Moderately Accelerating Forcing an 8-7 or 8-6 Downshift.
22-NA-0152023-10-14. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. This informational bulletin provides graphs to help identify possible issues that may cause shaking and shudders and what may be the cause of said issue.
21-NA-1202023-10-14. Service bulletin. POWER TRAIN; EQUIPMENT. This service bulletin provides a Diagnostic Tip for Noise, Vibration, and/or Harshness Issues/Clunk Noise Heard During Coast Down Event after the transfer case was removed from the transmission and reinstalled during a recent repair.
20-NA-1422023-10-10. Service bulletin. POWER TRAIN. This Technical bulletin provides a repair to correct a condition of Shudder/Surging While Driving.
23-NA-1532023-09-26. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
PIP5621D2023-09-18. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer technician that TAC recommends the utilization of the GDS2 software to aid in diagnosing automatic transmission concerns. TAC is requesting the GDS2 session logs be sent in before the dealer contacts TAC.
22-NA-1872023-09-15. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. This informational bulletin advises the tech to inspect the transfer case motor electrical connectors for possible damage or corrosion that might be caused by a damage grommet inside the electrical connector.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.